4-Nitrobenzyl chloroformate → HCID 13219817, compound

Participants

Reaction Steps

N,N-Diisopropylethylamine 496 l, 2.85 mmol) was added to a suspension of mercaptoamine hydrochloride 7* (173 mg, 1.24 mmol) in anhydrous MeCN (0.93 ml) and the resulting mixture was stirred under a N2 atmosphere with ice bath cooling for 5 minutes. Chloromethyl silane (204 l, 1.61 mmol) was added and the mixture was stirred at 0° for 10 minutes. A solution of p-nitrobenzyl chloroformate (267 mg, 1.24 mmol) in MeCN (0.31 ml) and more N,N-diisopropylethylamine (216 l, 1.24 mmol) were added and the resulting mixture was stirred at 0° for 30 minutes and at room temperature for 60 minutes. The mixture was diluted with EtOAc, washed with H2O, 1N HCl, 5% aq. NaHCO3, and brine, dried with MgSO4, filtered and evaporated i.v., to a pale yellow oil. The crude product was chromatographed on a EM silica gel 60 column (20 g) that was eluted with 2:1 hexane-ethyl acetate at a rate of 8 ml fractions/3.5 minutes. Fractions 16-22 gave the product 25* (198 mg) as a pale yellow oil which crystallized to an off-white solid on storage in a refrigeration.

Provenance & Evidence